The incident is believed to have happened on Monday afternoon around 4pm as neighbours heard noises.
The vandals are believed to have entered the paddock off the A338 Grafton Road between Burbage and East Grafton from the rear.
They smashed up two Land Rover Discovery vehicles, a third Land Rover being renovated, a Saab Convertible, a Ford Transit van, a flatbed lorry, two caravans and two vintage tractors.
Mrs Bushnell, of Fyfield near Marlborough, said today: "It has absolutely ruined our Christmas. It is just vandalism, utter vandalism.
"They have smashed windows and headlights on the vehicles and ransacked the shed.
"There are tools everywhere in the hedgerow and bushes and a kitchen knife that has come from somewhere. At this point we don't know what is missing.
"We didn't get to sleep properly last night because of what has happened. We are very upset."
Mrs Burbage, 50, said she and her husband Graham, also 50, own the paddock which lies behind a property owned by Mr Bushnell's 78-year-old parents.
She says the mindless vandalism has caused "thousands of pounds" worth of damage and that three of the vehicles will have to be written off.
Two caravans were destroyed, two vintage tractors had their headlights smashed and property was stolen.
The Saab convertible had its front lights smashed and the doors left open, while the Transit van, the Land Rover vehicles and a lorry were also damaged.
She added: "A neighbour heard banging around 4pm and the sound of a girl's voice.
"We believe this was done by a group of minors from either the Burbage or Grafton area.
"There is no way they came in from the side of the house. They must have come in from the back.
"There was definitely more than one person involved because of the amount of damage that was done.
"I am pleading for someone to have a heart and come forward before we take the information we have to the police."
Mrs Bushnell says that some names have been mentioned on social media and these will be passed on to the police.
The incident has now been reported to Wiltshire Police who are investigating.